在进行数据库的查询时，会经常遇到这样的情况：
例如想在一个用户数据库中查询他的用户名和他的密码，但恰好该用户使用的名字和密码中有特殊的字符，例如单引号，“|”号，双引号或者连字符“&”。
例如他的名字是1\'test，密码是A|&900
这时当你执行以下的查询语句时，肯定会报错：
SQL = "SELECT * FROM SecurityLevel WHERE UID=\'" & UserID & "\'"
SQL = SQL & " AND PWD=\'" & Password & "\'"
因为你的SQL将会是这样：
SELECT * FROM SecurityLevel WHERE UID=\'1\'test\'
AND PWD=\'A|&900\'

在SQL中，"|"为分割字段用的，显然会出错了。现在提供下面的几个函数 专门用来处理这些头疼的东西：
Function ReplaceStr (TextIn, ByVal SearchStr As String, _
ByVal Replacement As String, _
ByVal CompMode As Integer)
Dim WorkText As String, Pointer As Integer
If IsNull(TextIn) Then
ReplaceStr = Null
Else
WorkText = TextIn
Pointer = InStr(1, WorkText, SearchStr, CompMode)
Do While Pointer > 0
WorkText = Left(WorkText, Pointer - 1) & Replacement & _
Mid(WorkText, Pointer + Len(SearchStr))
Pointer = InStr(Pointer + Len(Replacement), WorkText, _
SearchStr, CompMode)
Loop
ReplaceStr = WorkText
End If
End Function

Function SQLFixup(TextIn)
SQLFixup = ReplaceStr(TextIn, "\'", "\'\'", 0)
End Function

Function JetSQLFixup(TextIn)
Dim Temp
Temp = ReplaceStr(TextIn, "\'", "\'\'", 0)
JetSQLFixup = ReplaceStr(Temp, "|", "\' & chr(124) & \'", 0)
End Function
Function FindFirstFixup(TextIn)
Dim Temp
Temp = ReplaceStr(TextIn, "\'", "\' & chr(39) & \'", 0)
FindFirstFixup = ReplaceStr(Temp, "|", "\' & chr(124) & \'", 0)
End Function

有了上面几个函数后，当你在执行一个sql前，请先使用
SQL = "SELECT * FROM SecurityLevel WHERE UID=\'" & SQLFixup(UserID) & "\'"
SQL = SQL & " AND PWD=\'" & SQLFixup(Password) & "\'"